1. Field of the Invention
The present invention relates to an electronic mail device for transmitting and receiving electronic mail, and more specifically to an Internet facsimile machine for transmitting and receiving image data as a file attached to the electronic mail.
2. Description of the Related Art
Recently, an Internet facsimile machine for transmitting and receiving image data of an original such as a document in the form of electronic mail is in widespread use. According to the Internet facsimile machine, the image data of the original read in from a scanning unit, which is provided within the Internet facsimile machine, is converted into the image data of a format capable of being attached to electronic mail, and can be transmitted to another Internet facsimile machine or the like capable of receiving the electronic mail which has the attached file of the image data.
Such a file attached to electronic mail includes a large amount of information and requires a certain period of time for transmitting or receiving. When the number of pages to be transmitted is large, for example, in the case the original is comprised of 100 to 200 pages, a long period of time is required. Moreover, in the Internet facsimile machine at the receiving side, after receiving the encrypted attached file, the attached file is decrypted. Furthermore, it is necessary to carry out dividing processing per each page or the like. As a result, it requires even longer period of time until completing the processing such as printing or distributing of the received image data.
Moreover, generally, the Internet facsimile machine at the transmitting side transmits image data under a certain format without confirming the ability of the Internet facsimile machine at the receiving side. This ability is, for example, an encrypting method of image data by which the image data can be received by the Internet facsimile machine at the receiving side, or a size of recording paper capable of being printed out (for example A3, A4 sizes). Therefore, it is difficult to transmit image data which is most appropriate to the ability of the Internet facsimile machine of the receiving side.
In the exchanging of the electronic mail accompanying delivery confirmation demand such as DSN (Delivery Status Notification) or MDN (Message Disposition Notification), the transmitting side establishes an SMTP (Simple Mail Transfer Protocol) session, and transmits the electronic mail with the delivery confirmation demand. After closing the SMTP session once, a new SMTP session is established, and the electronic mail of delivery confirmation is transmitted from the receiving side. Therefore, there was a problem in that it took a long period of time to receive the electronic mail of the delivery confirmation at the transmitting side.